[Suggestion] Add night light slider

[echeoquehaii]

Hi @qwreey75, first of all thank you so much for your work on this great extension!

I'd like to suggest a feature which I was using on previous gnome-shell versions through this extension. I think it's very handy to adjust the night light strength according to many factors, for example if watching a movie, working, reading, and so on, instead of having to go to display settings all the time.

[qwreey]

I will try to implement this when i have break time. thanks for your suggestion!

[echeoquehaii]

Thank you for considering this! :)